According to a spokesperson from the mostly indigenous protesters, Cleanton Ribeiro, more than 150 members from four local tribes began occupying a portion of the construction site where, when completed, the world's third largest hydroelectric dam would flood thousands of acres upon which they currently reside.

"They are demanding demarcation of their lands, the expulsion of invaders, an improved health system and running water," says Ribeiro, via the AFP. "They no longer believe in the promises made (by the consortium) and say they will leave only when concrete steps begin."

According reports from Al Jazeera in Brazil, the tribespeople have so far been effective in halting the dam's construction, to point. A federal judge has rejected requests from the builders to forcibly remove the protesters, though work on the unoccupied portions is still scheduled to continue.